JP2002023171A - Liquid crystal display device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the liquid crystal display device of the satisfactory characteristic of the angle of visibility, which prevents the delay of a response due to the influence of a data line or a gate electrode and the drop of panel transmissivity in a low application voltage area and whose opening rate can be enlarged. SOLUTION: The liquid crystal display device of an IPS system, a gate electrode 2 and a common electrode 3, and TFT, a data like and a pixel electrode 7 and a passivation film 8 through an interlayer insulating film are formed on a first transparent substrate 1 where TFT is formed. Liquid crystal 17 sandwiched by the first transparent substrate and a confronted second transparent substrate is rotated in a face which is almost parallel to the substrate by voltage applied between the pixel electrode and the common electrode, which are alternately formed in parallel. A partition 9a constituted of an insulating body is formed on the passivation film so that it is overlapped with the common electrode. Thus, liquid crystal in a pixel area is parted from liquid crystal oriented in a different direction by a DC voltage applied to the gate electrode or the data line and the response of liquid crystal and the characteristic of the angle of visibility are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method of manufacturing the same, and more particularly, to a liquid crystal display device in which a liquid crystal is applied in a plane substantially parallel to a substrate by a voltage applied between a pixel electrode formed on a TFT substrate and a common electrode. Driving IPS (In-Plane Switchi
The present invention relates to a liquid crystal display device of the ng) type and a manufacturing method thereof.

[0002]

2. Description of the Related Art An active matrix type liquid crystal display device using a thin film transistor (hereinafter abbreviated as TFT) as a switching element of a pixel has high quality image quality.
It is widely used as a monitor for space-saving desktop computers. Generally, an operation mode of a liquid crystal display device includes a twisted nematic (TN) method in which a director of aligned liquid crystal molecules is rotated in a direction perpendicular to a transparent substrate, and a liquid crystal display device in a direction parallel to the transparent substrate. There is an IPS system that rotates in the direction.

In the IPS type liquid crystal display device, a pixel electrode and a common electrode whose comb teeth are parallel to each other are alternately formed on a first transparent substrate on which a TFT is formed, and a voltage is applied between the electrodes to form a substrate. By forming an electric field parallel to the plane, the direction of the director of the liquid crystal is changed, thereby controlling the amount of transmitted light. Therefore, in this display method, since the director rotates in the substrate plane, there is a large relationship between the amount of transmitted light and the applied voltage when viewed from the direction of the director and when viewed from the normal direction of the substrate as in the case of the TN method. There is no problem that they differ from each other, and a good image can be obtained from a very wide viewing angle.

In such an IPS system, the liquid crystal layer is made to have a homogeneous alignment, sandwiched between two polarizing plates whose polarization axes are orthogonal to each other, and one of the polarization axes is made equal to the alignment direction of the liquid crystal molecules. In general, black display is performed when no voltage is applied, and liquid crystal molecules are twist-deformed in the direction of an electric field by applying a voltage between the pixel electrode and the common electrode to obtain white display. Is widely used because it can be stably reduced.

Here, a structure of a conventional liquid crystal display device will be described with reference to FIG. FIG. 21 shows a conventional IP
It is a figure which shows the structure of S liquid crystal display device, (a) is a top view, (b) is sectional drawing in the AA 'line of (a). A conventional liquid crystal display device includes a first transparent substrate 1 on which a TFT is formed and a color filter (CF).
Are formed and a liquid crystal 17 sandwiched between them. On the first transparent substrate 1, a gate electrode 2 and a data line 6 are formed substantially orthogonally. The TFTs 5 are arranged in a matrix at the intersections, and pixel electrodes 7 and common electrodes 3 which are mutually parallel are alternately formed in each pixel. On the second transparent substrate 11, a black matrix 12 for shielding extraneous light, a color layer 13 for displaying RGB three colors, and a flattening film 14 covering these are formed. .

An orientation film 18 is applied to the surfaces of the first transparent substrate 1 and the second transparent substrate 11, and a homogeneous orientation is provided between the two substrates at a predetermined angle in the longitudinal direction of the pixel electrode 7. The held liquid crystal 17 is held.
Polarizing plates 16a and 16b are attached to the outside of both substrates, and the polarizing axes of both polarizing plates are orthogonal to each other, and one of the polarizing axes is set parallel to the orientation direction of the liquid crystal. And TFT
By writing a potential to the pixel electrode 7 through the pixel electrode 5 and applying a horizontal electric field between the pixel electrode 7 and the common electrode 3, the liquid crystal 1
7 is twist-deformed in a plane parallel to the substrate to control the display.

[0007]

However, in the conventional liquid crystal display device, since a large voltage is applied to the gate electrode 2 and the data line 6, the liquid crystal 17 has a pixel electrode 7
Not only the electric field between the gate electrode 2 and the common electrode 3, but also the electric field between the gate line 2 and the common electrode 3 and between the data line 6 and the common electrode 3. There is a problem that the disturbance occurs.

This problem will be described with reference to FIGS. FIG. 22 is a timing chart showing the voltages applied to the gate electrode 2, the data line 6, and the common electrode 3. FIGS. 23 and 24 show the alignment state of the liquid crystal 17 in the white display near the data line 6 or the gate electrode 2. FIG. FIG. 25 is a diagram showing a potential distribution in the cell gap and an electric field acting on the liquid crystal 17.

First, as shown in FIG. 22, a DC voltage (Vcom) of about 4.5 V is applied to the common electrode 3 in the pixel, and this voltage is applied to the pixel electrode 7 via the data line 6.
The liquid crystal is rotated in the direction of the electric field by the difference from the voltage (Vd) applied to the data line 6, but a DC voltage of about 6.5 V higher than the potential of the common electrode 3 is always applied to the data line 6. I have. Further, -1 is applied to the gate electrode 2 at a predetermined cycle.
A pulse voltage (Vg) that rises from a low level of about 0 V to a high level of about 20 V is applied.
Therefore, the common electrode 3 has a data line 6 in addition to the pixel electrode 7.
And the voltage applied to the gate electrode 2, especially the DC voltage.

With respect to the influence of the DC potential of the data line 6 and the gate electrode 2, FIG.
Referring to FIG. 24, there is a potential difference of about 2 V between the reference potential of the data line 6 and the common electrode 3 as described above. Here, the electric field strength is proportional to the voltage and inversely proportional to the distance between the electrodes. However, since the area between the data line 6 and the common electrode 3 is an area shielded by a black matrix that does not contribute to display, the aperture ratio is reduced. In order to ensure the distance, the distance between the pixel electrode 7 and the common electrode 3 (5 to 10 μm)
It is narrower and is usually set to about 2 μm. Therefore,
A small electric field is generated between the data line 6 and the common electrode 3, but a large electric field is generated due to a small interval.

Referring to FIG. 23, the liquid crystal between the data line 6 and the common electrode 3 is always rotated in a direction different from the initial alignment direction by an electric field generated between the electrodes. The liquid crystal in the pixel (between the common electrode 3 and the pixel electrode 7) rotates in the direction of the electric field between the two electrodes in the white display state, but returns to the initial alignment direction in the black display state where the voltage is OFF. The liquid crystal tends to be oriented in different directions in the left and right regions of the drawing with the common electrode 3 as a boundary.

Here, the operation of a general liquid crystal will be described. In the liquid crystal, when the voltage is ON or OFF, each liquid crystal molecule does not rotate independently of each other.
Mutual molecules exert influence on each other on the basis of elastic properties, and other liquid crystal molecules rotate as one liquid crystal molecule rotates, whereby a group of liquid crystal molecules is twist-deformed.
That is, when the voltage is turned on / off, the elastic constants K11,
The elastic force corresponding to K22 and K33 acts to deform.

The operation of a liquid crystal having such an elastic characteristic is described as follows.
Considering the vicinity of the data line 6 in FIG. 23, the liquid crystal between the data line 6 and the common electrode 3 rotates in the direction of the electric field by the DC voltage and always faces in a certain direction. In a white display state where a voltage is applied, the liquid crystal between these electrodes rotates in the direction of an electric field (clockwise in the figure), and when returning to a black display state where no voltage is applied between these electrodes, Rotate clockwise. Therefore, in either case of the voltage ON / OFF, if the liquid crystal between the common electrode 3 and the pixel electrode 7 tries to rotate in a direction different from the direction of the liquid crystal near the data line 6, the elastic force of the liquid crystal causes the rotation. The response is slowed down by the movement being hindered. This problem appears particularly in black display with the voltage OFF.

Similarly, considering the vicinity of the gate electrode 2, the distance between the gate electrode 2 and the common electrode 3 is set to about 8 μm, which is larger than that of the data line 6.
Between the low level of the gate electrode 2 and the common electrode 3,
As described above, since there is a large potential difference of about 15 V, the liquid crystal between the gate electrode 2 and the common electrode 3 is rotated by a strong electric field generated by the large potential difference.

The operation of the liquid crystal will be described with reference to FIG. 24. The liquid crystal between the gate electrode 2 and the common electrode 3 is D
The liquid crystal between the common electrode 3 and the pixel electrode 7 has a gate which always rotates in the direction of the electric field (vertical direction in the figure) due to the C voltage. If an attempt is made to rotate the liquid crystal in a direction different from the direction of the liquid crystal in the vicinity of the electrode 2, the movement is hindered by the elastic force of the liquid crystal, resulting in a slow response.

Such an effect of the data line 6 or the gate electrode 2 appears remarkably in a portion where the electric field between the pixel electrode 7 and the common electrode 3 is weak. That is, as shown in FIG. 25, the electric field between the comb-tooth electrodes becomes smaller as approaching the opposing CF substrate, and the liquid crystal molecules closer to the CF substrate are affected by the data line 6 or the gate electrode 2 and the response becomes slower. Further, the threshold voltage of the liquid crystal becomes large, and the panel transmittance in a region where the applied voltage is low is reduced. Further, the orientation of the liquid crystal around the pixel is disturbed by the electric field between the data line 6 or the gate electrode 2 and the common electrode 3, and coloring occurs not only in response to returning to black display but also in white display. And other problems.

The present invention has been made in view of the above problems, and a main object of the present invention is to prevent a response delay due to the influence of a data line or a gate electrode and a decrease in panel transmittance in a low applied voltage region. It is still another object of the present invention to provide a liquid crystal display device having good viewing angle characteristics, which can increase the aperture ratio.

[0018]

In order to achieve the above object, the present invention comprises a pair of opposed substrates and a liquid crystal sandwiched between the pair of substrates. A plurality of gate lines and a plurality of data lines substantially orthogonal to each other; a thin film transistor disposed near an intersection of the gate line and the data line; At least a pixel electrode and a common electrode which are arranged in a pixel region to form a pixel region, and a voltage applied between the pixel electrode and the common electrode,
IPS for rotating the liquid crystal in a plane substantially parallel to the substrate
In a liquid crystal display device of a system, at least one of the pair of substrates is formed with a partition for dividing the liquid crystal inside and outside the pixel region at least in part.

In the present invention, it is preferable that the partition is formed so as to overlap with the common electrode when viewed from a normal direction of the substrate.

Further, in the present invention, the partition is:
It may be configured to be continuously formed so as to surround the pixel region.

The manufacturing method according to the present invention includes a step of forming a gate electrode and a common electrode on one substrate, a step of depositing a first insulating film on the gate electrode and the common electrode, Forming at least a thin film transistor, a data line, and a pixel electrode on the insulating film, and a step of depositing a second insulating film on the data line and the pixel electrode, wherein the pixel electrode and the common electrode IPS that rotates the liquid crystal held between the one substrate and the opposing substrate in a plane substantially parallel to the substrate by a voltage applied between the substrates.
In the method for manufacturing a liquid crystal display device of the system, a step of forming a partition made of an insulator on the second insulating film so as to overlap with the common electrode when viewed from a normal direction of the substrate is included.

The manufacturing method according to the present invention further comprises a step of forming a gate electrode and a common electrode on one substrate, a step of depositing a first insulating film on the gate electrode and the common electrode, Forming a thin film transistor, a data line, and a pixel electrode on the first insulating film; forming an RGB color layer on the data line and the pixel electrode; and forming a flattening film on the color layer. And a liquid crystal sandwiched between the one side substrate and the opposing substrate by a voltage applied between the pixel electrode and the common electrode, the surface being substantially parallel to the substrate. In the method of manufacturing an IPS-type liquid crystal display device rotated inside, in forming the color layer, the color layer of any one of RGB is formed in a region surrounded by the gate electrode and the data line; Normal direction of substrate Look al, is intended to include the step of forming the partition by disposing the color of the color layer is different from color of layer material so as to overlap with the common electrode.

The manufacturing method of the present invention further comprises a step of forming a gate electrode and a common electrode on one substrate, a step of depositing a first insulating film on the gate electrode and the common electrode, Forming at least a thin film transistor, a data line, and a pixel electrode on a first insulating film; and depositing a second insulating film on the data line and the pixel electrode. A voltage applied between the substrate and the common electrode causes the liquid crystal held between the one substrate and the opposing substrate to rotate in a plane substantially parallel to the substrate.
In the method for manufacturing a liquid crystal display device of a PS system,
Forming an insulating film, forming a groove penetrating to the common electrode in a region overlapping with the common electrode when viewed from the normal direction of the substrate, and forming a partition made of a conductor inside and at an upper portion of the groove. And the step of performing.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of the liquid crystal display device according to the present invention, a gate electrode 2 and a common electrode 3 are provided on a first transparent substrate on which a TFT is formed via an interlayer insulating film. A TFT, a data line 6, and a pixel electrode 7,
A liquid crystal formed between the first transparent substrate and the opposing second transparent substrate by a voltage applied between the pixel electrode and the common electrode which are formed with the passivation film 8 and are formed in parallel and alternately with each other. In a liquid crystal display device of the IPS type in which the liquid crystal 17 is rotated in a plane substantially parallel to the substrate, a partition 9a made of an insulator is formed on the passivation film so as to overlap with the common electrode, and the partition allows the liquid crystal in the pixel region to be separated from the common electrode. A liquid crystal which is oriented in different directions by a DC voltage applied to a gate electrode or a data line is separated from each other to improve the response and viewing angle characteristics of the liquid crystal.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention;

[Embodiment 1] First, an IPS mode liquid crystal display device according to a first embodiment of the present invention will be described with reference to FIGS. 1A and 1B are diagrams showing a structure of a liquid crystal display device according to a first embodiment, wherein FIG. 1A is a plan view,
(B) is a sectional view taken along line AA 'of (a). 2 to 7 are views showing a method of manufacturing the liquid crystal display device of the present embodiment, wherein (a) is a plan view, (b) is a line BB 'of (a), and CC'. It is sectional drawing in the line, DD 'line, a gate terminal, and a drain terminal. 8 and 9
FIG. 8 is a diagram for explaining the effect of the present embodiment, FIG. 8 is a diagram showing the correlation between the applied voltage and the panel transmittance, and FIG. 9 is a diagram showing the correlation between the applied voltage and the response.

Referring to FIG. 1, the structure of the IPS liquid crystal display device of the present embodiment will be described. The liquid crystal display device of the present embodiment has a first transparent substrate 1 for forming a TFT and a second transparent substrate for forming a CF. Transparent substrate 11 and liquid crystal 17 sandwiched therebetween
On the first transparent substrate 1 side, a gate electrode 2 and a data line 6 are formed substantially orthogonally, and TFTs 5 are arranged in a matrix at intersections thereof to form one pixel. Each pixel has a pixel electrode 7 and a common electrode 3 formed in parallel and alternately with each other.
The common electrode 3 is connected to a source electrode of the FT, and the common electrode 3 is connected to a common electrode wiring extending in parallel with the gate electrode 2. Then, a passivation film 8 is formed so as to cover these electrodes.
Are formed, and a partition 9a made of an insulator for dividing the liquid crystal layer is formed on the common electrode 3 around the pixel.

On the other hand, on the second transparent substrate 11, a black matrix 12 for shielding extra light on the gate electrode 2, the data line 6 and between these and the pixel display section is provided.
A color layer 13 for performing color display of three colors RGB is formed, and a flattening film 14 is formed so as to cover the color layer 13.

An alignment film 18 is applied to the surfaces of the first transparent substrate 1 and the second transparent substrate 11, and a homogeneous alignment is formed between the two substrates so as to form a predetermined angle with the data line 6. The held liquid crystal 17 is held. Also,
Polarizing plates 16a and 16b are attached to the outside of both substrates,
The polarization axes of both polarizers are orthogonal to each other, and one polarization axis is set to be parallel to the orientation direction of the liquid crystal 17. A constant common potential is supplied to all the common electrodes 3 through the common electrode wiring. A potential is written to the pixel electrode 7 via the TFT 5, and a horizontal electric field is generated between the pixel electrode 7 and the common electrode 3. By giving, the liquid crystal 17 is twist-deformed in a plane parallel to the substrate to control the display.

Next, the partition 9 of such a liquid crystal display device will be described.
FIG. 2 shows a method of manufacturing a TFT-side substrate on which a is formed.
This will be described with reference to FIGS. First, as shown in FIG. 2, after depositing a metal such as Cr on the first transparent substrate 1 by a sputtering method or the like, a resist is applied, and exposure and development are performed using a known photolithography technique, and a predetermined Is formed. Then, using the resist pattern as a mask, the exposed Cr is removed by wet etching to form a gate electrode 2 and a common electrode 3.

Next, as shown in FIG. 3, after an insulating film such as a silicon oxide film 4a is deposited by a CVD method or the like, a silicon nitride film 4b, amorphous silicon (a-Si5a) and an n-type Crystalline silicon (n ⁺ a-Si5b)
The TFT 5 is formed by continuously forming a film by using the VD method or the like, performing dry etching using the resist pattern formed thereon as a mask, and removing the exposed a-Si 5a and n ⁺ a-Si 5b.

Next, as shown in FIG. 4, after depositing a metal such as Cr by a sputtering method or the like, a resist pattern having a predetermined shape is formed, and wet and dry etching is performed using the resist pattern as a mask. , Data lines 6, source / drain electrodes, and pixel electrodes 7 are formed. Thereafter, channel dry etching is performed using the source / drain electrodes made of Cr as a mask to remove the exposed n ⁺ a-Si 5b in the TFT 5 region.

Next, as shown in FIG. 5, a passivation film 8 made of a silicon nitride film or the like is deposited by a plasma CVD method or the like, and the resist pattern formed thereon is used as a mask to form a gate terminal and a drain terminal. The passivation film 8, the silicon nitride film 4b, and the silicon oxide film 4a are removed by wet or dry etching to expose the gate terminal and drain terminal metal films.

Then, as shown in FIG.
um Thin Oxide) using a sputtering method, etc.
A predetermined resist pattern is formed, and using the mask as a mask, the exposed ITO is removed by wet etching, and ITO is exposed on the exposed metal film of the gate terminal and the drain terminal.
Is formed. After that, annealing is performed under predetermined conditions.

In the conventional method of manufacturing a TFT substrate, an alignment film 18 is applied next.
Is formed at a position corresponding to the common electrode 3 to partition the pixel region from a region near the gate electrode 2 and the data line 6. That is, as shown in FIG. 7, an insulator made of a photosensitive resin such as a resist or polyimide is deposited on the entire surface of the substrate to a predetermined thickness, and only a predetermined region of the common electrode 3 is exposed to light by using a photomask to shield light. ,
Development is performed to form a partition 9 a on the common electrode 3.
After the partition 9a is solidified by firing, TF
An alignment film 18 is applied to the T-side substrate and the CF-side substrate, the two substrates are adhered to each other, and a liquid crystal 17 is injected into a gap therebetween.

Here, the partition 9a provided on the TFT substrate
Is provided to separate the pixel region from the region near the gate electrode 2 and the data line 6, the height of the partition 9a is equal to the cell gap between the two substrates, that is, the partition 9a
It is preferable that the alignment film 18 applied to the second transparent substrate 11 is set in contact with the alignment film 18 on the second transparent substrate 11 side. Also,
In the present embodiment, a gap is formed between the partitions 9a. This gap is to make it easier for the liquid crystal 17 to enter the pixel when the liquid crystal 17 is injected. It can be appropriately set to an optimum value according to the viscosity of the resin.

As described above, in the liquid crystal display device of the present embodiment, the partition 9a is formed in the upper layer of the common electrode 3, and the liquid crystal 17 in the pixel region and the data line 6 are formed by the partition 9a.
And the liquid crystal 17 near the gate electrode 2 is separated.
Even when the liquid crystal in that region rotates in a different direction from the liquid crystal inside the pixel due to the electric field between the DC voltage applied to the data line 6 and the gate electrode 2 and the common electrode 3, the liquid crystal inside the pixel remains The alignment direction is controlled only by the electric field between the common electrode 3 and the pixel electrode 7.

That is, in the liquid crystal display device having the conventional structure shown in FIGS. 23 and 24, when the liquid crystal in the pixel tries to rotate by the electric field between the pixel electrode 7 and the common electrode 3, the data line 6 and the gate The rotation was hindered by the elastic force between the liquid crystal having different orientations in the vicinity of the electrode 2. In this embodiment, since the partition 9a is formed in the upper layer of the common electrode 3, the data line 6 and the gate electrode are formed. The elastic force of the liquid crystal in the vicinity of 2 does not act on the liquid crystal in the pixel, and the liquid crystal in the pixel can be quickly rotated.

This effect will be described with reference to FIGS. 8 and 9. As for the panel transmittance, as shown in FIG. 8, the conventional liquid crystal panel (solid line and open square) inhibits the rotation of the liquid crystal. The panel transmittance peaked at a high applied voltage. However, in the configuration of the present embodiment (the dashed line and the black square in the drawing), the liquid crystal in the pixel region was aligned in the alignment direction of the liquid crystal near the data line 6 and the gate electrode 2. Is not dragged, the threshold voltage Vth of the liquid crystal can be lowered, and the peak of the panel transmittance can be shifted to the lower voltage side.

As for the response time, as shown in FIG. 9, the conventional one (solid line and open square in the figure) generally has a long response time, and especially on the low voltage side, the influence of the data line 6 and the gate electrode 2 is large. The response time has increased in response to this, however, in the configuration of the present embodiment (indicated by the dashed-dotted black line in the figure), the partition 9a
As a result, the liquid crystal in the vicinity of the data line 6 and the gate electrode 2 is not affected, so that the liquid crystal can be quickly rotated in all the applied voltage regions, and the response can be improved.

Conventionally, the data line 6 and the gate electrode 2
In order to alleviate the effect of the above, the distance between the two electrodes and the common electrode 3 and the width of the common electrode 3 around the pixel area had to be increased. In addition, since the influence of the gate electrode 2 is suppressed, the distance between the data line 6 and the gate electrode 2 and the common electrode 3 and the width of the common electrode 3 can be reduced, so that the light shielding area is reduced and the aperture ratio is improved. be able to.

The liquid crystal 17 inside the pixel does not rotate in the direction of the electric field between the data line 6 and the gate electrode 2 and the common electrode 3 due to the partition 9a, so that the alignment direction of the liquid crystal near the common electrode 3 is disturbed. Can be prevented,
A liquid crystal display device having good viewing angle characteristics can be obtained without causing a problem such as coloring in the vicinity of the common electrode 3 during white display.

Further, since the partition 9a is formed of a resin applied to a uniform film thickness, its height is uniform in the plane of the liquid crystal display device so that the partition 9a comes into contact with the second transparent substrate. By laminating the two substrates together, it is possible to obtain an effect that the cell gap between the substrates can be controlled uniformly and accurately.

In the present embodiment, an example in which the partition 9a is formed on the common electrode 3 has been described. However, the present invention is not limited to the above-described embodiment, and the partition 9a is used to separate liquid crystals having different alignment directions. Any structure may be used as long as it is divided, for example, it may be formed in a region between the data line 6 or the gate electrode 2 and the common electrode 3 or in a region inside the pixel.
The partition 9a may be formed on the second transparent substrate 11 side.
Further, for example, in a multi-domain structure in which the pixel electrode has a shape having a bending point and the liquid crystal 17 is oriented in a plurality of directions in the pixel, the partition 9a is provided in the pixel to independently control the orientation direction between domains. You can also.

Embodiment 2 Next, an IPS type liquid crystal display device according to a second embodiment of the present invention will be described with reference to FIG. FIGS. 10A and 10B are diagrams showing the structure of the liquid crystal display device according to the second embodiment, where FIG. 10A is a plan view and FIG.
FIG. 3A is a cross-sectional view taken along line AA ′ of FIG. In this embodiment, the shape of the partition is different from that of the first embodiment, and the structure of the other parts is the same as that of the first embodiment.
This is the same as the embodiment.

That is, in the above-described first embodiment, the partition 9a provided on the first transparent substrate 1 is formed such that gaps are formed at predetermined intervals to facilitate injection of the liquid crystal 17. In this embodiment, the partition 9a is connected to the common electrode 3
It is characterized by being formed continuously in a single stroke on the upper layer. By continuously forming the partitions 9a in this manner, the liquid crystal in the pixel region and the liquid crystal in the vicinity of the data line 6 and the gate electrode 2 are completely separated from each other.
Even if the liquid crystal in that region is oriented in a different direction from the liquid crystal inside the pixel due to the electric field between the DC voltage applied to the gate electrode 2 and the common electrode 3, the liquid crystal inside the pixel The alignment direction can be controlled only by the electric field between 7 and the common electrode 3.

In particular, when returning from the white display state to the black display state in which no voltage is applied between the electrodes, the display is quickly affected by the elastic force between the data line 6 and the liquid crystal near the gate electrode 2. Since the alignment direction can be rotated in the initial alignment direction, and the alignment direction of the liquid crystal in the vicinity of the common electrode 3 can be prevented from being disturbed, no coloring occurs near the common electrode 3 during white display. The first
It is possible to obtain a liquid crystal display device having a quicker response and better viewing angle characteristics than the embodiment.

The aperture ratio can be improved by reducing the distance between the data line 6 and the gate electrode 2 and the common electrode 3 and the width of the common electrode 3, and the partition 9 a can be formed on the second transparent substrate 11. As in the first embodiment, the cell gap between the substrates can be uniformly and accurately controlled by affixing them so as to abut.

In this embodiment, since the partition 9a is formed continuously on the upper layer of the common electrode 3, it is difficult to inject the liquid crystal 17 into the partition 9a by using a vacuum injection method. Partition 9a by using the drop-injection method
The liquid crystal 17 can be uniformly injected into and out of the device. In addition, although the above effect is somewhat reduced, the liquid crystal can be easily injected by setting the height of the partition 9a slightly lower than the cell gap.

Embodiment 3 Next, an IPS type liquid crystal display device according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 11 to FIG.
13A and 13B are diagrams showing the structure of the liquid crystal display device according to the embodiment of the present invention, wherein FIG. 11A and FIG. 13A are plan views, and FIG.
FIG. 12 is a sectional view taken along the line A-A ′, and FIG.
3 is a sectional view of a pixel adjacent to FIG. In this embodiment,
Unlike the first and second embodiments, a color layer is provided on the first transparent substrate side, and a partition is formed using the color layer.

The method of manufacturing the IPS liquid crystal display device according to this embodiment will be briefly described. First, similarly to the above-described embodiment, the gate electrode 2 and the common electrode 3 are formed on the first transparent substrate 1.
Are formed, the data line 6 and the pixel electrode 7 are formed via the interlayer insulating film 4. Next, in the present embodiment, RGB3
Color layer (R) 13a, color layer (G) 13b, color layer (B)
13c is sequentially formed on adjacent pixels.
A color layer different in color from the color layer of each pixel is formed as the partition 9b.

For example, FIG. 11B shows a cross section of a pixel on which the color layer (R) 13a is formed among three color layers of RGB. In this case, first, the color layer ( R) 13
a is formed in a region surrounded by the gate electrode 2 and the data line 6, and then the color layer (G) 13b is formed in an adjacent pixel and corresponds to the common electrode 2 on the color layer (R) 13a. It is also deposited on parts. After that, the color layer (B) 13c is formed on the adjacent pixel on the opposite side, and is further deposited on the portion where the color layer (G) 13b is deposited on the color layer (R) 13a. Then, a partition 9b including the color layer (G) 13b and the color layer (B) 13c is formed on the color layer (R) 13a.

Thereafter, a flattening film 14 is deposited so as to cover the color layer 13 and the partition 9b, and an orientation film 18 is applied to form a first film.
Is formed. On the other hand, only the alignment film 18 is formed on the second transparent substrate 11 side, and the liquid crystal 17 is held between the two substrates. Although the black matrix 12 is not shown in FIGS.
May be formed on either the first transparent substrate 1 or the second transparent substrate 11, and when formed on the first transparent substrate 1,
A second transparent substrate 1 is provided on a layer between the data line 6 and the color layer 13.
When it is formed to be 1, it may be formed below the alignment film 18.

As described above, the color layer 13 is formed on the first transparent substrate 1.
In the liquid crystal display device having the structure formed in the above, a color layer different in color from the color layer 13 formed in the pixel is stacked and deposited, and this is used as the partition 9b, so that the partition 9c can be formed without newly adding a process. Can be formed first
Also, the number of steps can be reduced as compared with the second embodiment. The pixel on which the color layer (G) 13b is formed is shown in FIG.
As shown in FIG. 12A, the pixel on which the color layer (B) 13c is formed has a structure as shown in FIG.

Further, in the liquid crystal display device having such a structure, by forming the black matrix 12 together with the color layer 13 on the first transparent substrate 1, the color layer 13 and the black matrix 12, the gate electrode 2, the data line 6 and the common electrode 3 can be maintained more accurately, and the design margin can be reduced. Therefore, the aperture ratio can be further increased as compared with the first and second embodiments. it can.

As shown in FIG. 13, a partition 9b can be formed by depositing a flattening film 14 on the color layer 13 and depositing the color layer 13 or the black matrix 12 thereon. If the process can not be reduced,
Higher partitions can be easily formed than in the case of an insulator. The partitions 9b may be formed in pieces at predetermined intervals as shown in the figure or may be formed continuously as in the second embodiment, and the height of the partitions 9b is different from the cell gap. As with the first and second embodiments, the same or lower values may be used.

Fourth Embodiment Next, an IPS type liquid crystal display device according to a fourth embodiment of the present invention will be described with reference to FIGS. FIGS. 14A and 14B are diagrams showing the structure of the liquid crystal display device according to the fourth embodiment, wherein FIG. 14A is a plan view, and FIG. 14B is a cross-sectional view taken along line AA ′ of FIG. 15 to 20 are views showing a method of manufacturing the liquid crystal display device of the present embodiment, wherein (a) is a plan view and (b)
FIG. 3A is a cross-sectional view taken along line BB ′, line CC ′, line DD ′, and a gate terminal and a drain terminal in FIG. In addition,
This embodiment is different from the first to third embodiments described above.
The partition is formed of a conductor.

Referring to FIG. 14, the structure of the IPS liquid crystal display device of the present embodiment will be described. This liquid crystal display device has a first transparent substrate 1 on which a TFT is formed and a second transparent substrate 11 on which a CF is formed. And a liquid crystal 17 sandwiched between them. The first transparent substrate 1 has a gate electrode 2,
The data line 6 and the TFT 5 are arranged to form one pixel,
Each pixel is provided with a pixel electrode 7 and a common electrode 3. Then, a partition 9 made of a conductor is provided on the common electrode 3.
c is formed.

On the other hand, on the second transparent substrate 11, a black matrix 12 for shielding extra light and a color layer 13 are provided.
Further, an alignment film 18 is applied to both substrates, and a liquid crystal 17 which is homogeneously aligned so as to form a predetermined angle with the data line 6 is sandwiched between the substrates. Polarizing plates 16a and 16b are provided outside the two substrates.
Are attached so that the polarizing axes of both polarizing plates are orthogonal to each other, and one of the polarizing axes is set to be parallel to the alignment direction of the liquid crystal 17.

Next, a method of manufacturing the TFT-side substrate of such a liquid crystal display device will be described with reference to FIGS. First, as in the first embodiment, the first
After a metal such as Cr is deposited on the transparent substrate 1 by sputtering or the like, wet etching is performed using the resist pattern formed thereon as a mask to form the gate electrode 2 and the common electrode 3 (see FIG. 15).

Next, as shown in FIG. 16, after a gate insulating film such as a silicon oxide film 4a is deposited by a CVD method or the like, a silicon nitride film 4b, a-Si 5a and n ⁺ a-S
i5b is continuously formed using a plasma CVD method or the like,
Dry etching is performed using the resist pattern as a mask, and the exposed a-Si 5a and n ⁺ a-Si 5b are etched to form a TFT 5.

Thereafter, as shown in FIG. 17, after depositing a metal such as Cr by a sputtering method or the like, wet and dry etching is performed using a resist pattern as a mask to form a data line 6, a source / drain electrode, and a pixel electrode. Form 3 Thereafter, channel dry etching is performed using the source / drain electrodes made of Cr as a mask,
The exposed n ⁺ a-Si 5b in the TFT 5 region is removed.

Next, a passivation film 8 made of a silicon nitride film or the like is deposited by a plasma CVD method or the like, and the passivation film 8, the silicon nitride film 5b and the silicon oxide film 5a are wet- and dry-etched using the resist pattern as a mask. In this embodiment, as shown in FIG. 18, in addition to the gate terminal and the drain terminal, the passivation film 8, the silicon nitride film 5b, and the silicon oxide film in the region where the partition 9c is formed on the common electrode 3 are formed. 5a is also removed.

Then, as shown in FIG. 19, after depositing ITO by sputtering or the like, the exposed ITO is removed by wet etching using the resist pattern as a mask, and the gate terminal and the drain terminal are exposed on the exposed metal film. Then, an electrode terminal 10 made of ITO is formed, and then annealing is performed under predetermined conditions.

Next, in this embodiment, a conductor such as Cr is deposited on the entire surface of the substrate with a predetermined film thickness, and the exposed Cr is removed by wet or dry etching using the resist pattern as a mask to form the conductor. The partition 9c is formed in a predetermined area on the common electrode 3 (see FIG. 20).
Then, an orientation film 18 is applied to the first transparent substrate 1 and the second transparent substrate 11, the two substrates are adhered to each other, and a liquid crystal 17 is injected into a gap therebetween.

As described above, in the liquid crystal display device of this embodiment, the partition 9 c made of a conductor such as Cr is formed on the common electrode 3.
Is formed, and the liquid crystal in the pixel region is separated from the liquid crystal in the vicinity of the data line 6 and the gate electrode 2 by the partition 9c, so that the liquid crystal in the vicinity of the data line 6 and the gate electrode 2 is oriented in a different direction from the inside of the pixel. The liquid crystal inside the pixel is not affected, and
Since the partition 9c is kept at the same potential as the common electrode 3,
The electric field generated between the data line 6 and the gate electrode 2 and the common electrode 3 can be prevented from entering the inside of the pixel, and the liquid crystal inside the pixel can be accurately adjusted only by the electric field between the pixel electrode 7 and the common electrode 3. Can be controlled.

This effect will be described with reference to FIGS. 8 and 9. As for the panel transmittance, as shown in FIG. 8, the conventional panel (solid line and open square) shows a panel with a high applied voltage of about 6 V. Although the transmittance was at a peak, the liquid crystal in the pixel region was not dragged in the alignment direction of the liquid crystal in the vicinity of the data line 6 and the gate electrode 2 in the configuration of the present embodiment (dashed line and open triangle). In addition, since it is not affected by the electric field of the data line 6 and the gate electrode 2, the threshold voltage V
th can be reduced, and the peak of the panel transmittance can be further shifted to a lower voltage side than in the first embodiment.

Regarding the response time, as shown in FIG. 9, the conventional (solid line and open square) in FIG. 9 has a slow response as a whole, and in particular, the data line 6 and the gate electrode 2 on the low voltage side.
, The response time is increased due to the influence of the above. However, in the configuration of the present embodiment (the broken triangle in the figure), the liquid crystal is rapidly rotated in all the applied voltage regions from the low voltage region to the high voltage region. Therefore, the response can be further improved as compared with the first embodiment.

This effect is remarkable in the case where the cell gap is wider than the distance between the pixel electrode 7 and the common electrode 3 and in the black display state where no voltage is applied between these electrodes. That is, in the above-described first to third embodiments, the partitions 9a and 9b are formed to separate the pixel region from the liquid crystal in the vicinity of the data line 6 and the gate electrode 2, thereby delaying the response of the liquid crystal based on the elastic characteristic. Can be improved, but since the partitions 9a and 9b are formed of an insulator,
On the side of the second transparent substrate 11 where the electric field is small or in the black display state where no voltage is applied, the data line 6 and the gate electrode 2
Was affected by the electric field due to the DC voltage. However, in this embodiment, the electric field due to the DC voltage can be cut off by forming the partition 9c with a conductor, so that the response and the viewing angle characteristics can be improved.

By forming the partition 9c made of a conductor, the distance between the gate electrode 2 and the data line 6 and the common electrode 3 can be further reduced. It is also possible to increase the aperture ratio. Furthermore, the partition 9c can be used as a light-shielding material, and light leakage can be prevented together with the black matrix 12.

In this embodiment, an example is described in which the partition 9c is formed on the first transparent substrate 1 using Cr and the partition 9c is connected to the common electrode 3. However, the present invention is not limited to this embodiment. However, for example, the partition 9c may be formed using another metal such as Ti, tungsten, and ITO. Further, the partition 9c does not need to be connected to the common electrode 3, and in that case, it can be formed on the second transparent substrate 11 side.

[0072]

As described above, according to the configuration of the IPS liquid crystal display device of the present invention, the following effects can be obtained.

The first effect of the present invention is that a partition made of an insulator, a color layer, or a conductor is provided on an upper layer of a common electrode on the outer periphery of a pixel region to divide liquid crystal inside and outside the pixel region, thereby forming a gate electrode or a data line. The effect of liquid crystal aligned in a direction different from that of the pixel region can be suppressed by the DC voltage applied to the pixel region. That is, the response is large, the response is fast, and the disturbance of the alignment direction can be prevented.

The second effect of the present invention is that it is hardly affected by the DC voltage applied to the gate electrode or the data line, so that the distance between the gate electrode or the data line and the common electrode and the area around the pixel region are reduced. This means that the width of the common electrode can be reduced, the light blocking area can be reduced, and the aperture ratio can be increased.

A third effect of the present invention is that the electric field generated between the gate electrode or the data line and the common electrode is shielded by forming the partition with a conductor and connecting the common electrode to the common electrode. That is, the alignment direction of the liquid crystal can be accurately controlled, and leakage of light can be prevented by shielding the light with a conductor.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a structure of a liquid crystal display device according to a first embodiment of the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA ′ of FIG. .

FIGS. 2A and 2B are views showing a method for manufacturing the liquid crystal display device according to the first embodiment of the present invention, wherein FIG. 2A is a plan view and FIG.

3A and 3B are diagrams illustrating a method for manufacturing the liquid crystal display device according to the first embodiment of the present invention, wherein FIG. 3A is a plan view and FIG. 3B is a cross-sectional view.

4A and 4B are diagrams illustrating a method for manufacturing the liquid crystal display device according to the first embodiment of the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a cross-sectional view.

5A and 5B are diagrams showing a method for manufacturing the liquid crystal display device according to the first embodiment of the present invention, wherein FIG. 5A is a plan view and FIG. 5B is a cross-sectional view.

6A and 6B are diagrams showing a method for manufacturing the liquid crystal display device according to the first embodiment of the present invention, wherein FIG. 6A is a plan view and FIG. 6B is a cross-sectional view.

7A and 7B are diagrams showing a method for manufacturing the liquid crystal display device according to the first embodiment of the present invention, wherein FIG. 7A is a plan view and FIG. 7B is a cross-sectional view.

FIG. 8 is a diagram illustrating the effect of the liquid crystal display device according to the first embodiment of the present invention, and is a diagram illustrating a correlation between an applied voltage and panel transmittance.

FIG. 9 is a diagram illustrating the effect of the liquid crystal display device according to the first embodiment of the present invention, and is a diagram illustrating a correlation between an applied voltage and a response time.

FIGS. 10A and 10B are diagrams showing a structure of a liquid crystal display device according to a second embodiment of the present invention, wherein FIG. 10A is a plan view and FIG.
3 is a sectional view taken along line AA ′ of FIG.

FIGS. 11A and 11B are diagrams showing a structure of a liquid crystal display device according to a third embodiment of the present invention, wherein FIG. 11A is a plan view and FIG.
3 is a sectional view taken along line AA ′ of FIG.

FIG. 12 is a diagram illustrating a structure of a liquid crystal display device according to a third embodiment of the present invention, and is a cross-sectional view of a pixel adjacent to FIG. 11;

FIGS. 13A and 13B are diagrams showing a structure of a liquid crystal display device according to a third embodiment of the present invention, wherein FIG. 13A is a plan view and FIG.
3 is a sectional view taken along line AA ′ of FIG.

FIGS. 14A and 14B are diagrams showing a structure of a liquid crystal display device according to a fourth embodiment of the present invention, wherein FIG. 14A is a plan view and FIG.
3 is a sectional view taken along line AA ′ of FIG.

15A and 15B are diagrams showing a method for manufacturing a liquid crystal display device according to a fourth embodiment of the present invention, wherein FIG. 15A is a plan view and FIG. 15B is a cross-sectional view.

FIGS. 16A and 16B are views showing a method for manufacturing a liquid crystal display device according to a fourth embodiment of the present invention, wherein FIG. 16A is a plan view and FIG.

17A and 17B are diagrams showing a method for manufacturing a liquid crystal display device according to a fourth embodiment of the present invention, wherein FIG. 17A is a plan view and FIG. 17B is a cross-sectional view.

FIGS. 18A and 18B are diagrams illustrating a method for manufacturing the liquid crystal display device according to the fourth embodiment of the present invention, wherein FIG. 18A is a plan view and FIG.

FIGS. 19A and 19B are diagrams showing a method for manufacturing a liquid crystal display device according to a fourth embodiment of the present invention, wherein FIG. 19A is a plan view and FIG.

FIGS. 20A and 20B are diagrams showing a method for manufacturing the liquid crystal display device according to the fourth embodiment of the present invention, wherein FIG. 20A is a plan view and FIG.

FIG. 21 is a view showing a structure of a conventional liquid crystal display device;
(A) is a plan view, and (b) is a cross-sectional view taken along line AA 'of (a).

FIG. 22 is a timing chart showing a voltage applied to each electrode of the liquid crystal display device.

FIG. 23 is a diagram showing an alignment state of liquid crystal in the vicinity of a data line of a conventional liquid crystal display device.

FIG. 24 is a diagram showing an alignment state of liquid crystal near a gate electrode of a conventional liquid crystal display device.

FIG. 25 is a diagram showing an equipotential surface and an electric field direction of a conventional liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st transparent substrate 2 Gate electrode 3 Common electrode 4 Interlayer insulating film 4a Silicon oxide film 4b Silicon nitride film 5 TFT 5a a-Si 5bn ⁺ a-Si 6 Data line 7 Pixel electrode 8 Passivation film 9a, 9b, 9c Partition 10 Terminal electrode 11 Second transparent substrate 12 Black matrix 13 Color layer 13a Color layer (R) 13b Color layer (G) 13c Color layer (B) 14 Flattening film 15 Conductive film 16a, 16b Polarizing film 17 Liquid crystal 18 Orientation film

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H089 LA10 MA04X NA14 NA17 NA24 NA60 PA03 QA11 QA14 QA15 RA04 RA18 SA01 TA04 TA09 2H090 KA04 KA18 LA02 LA04 MA02 2H092 GA14 JA26 JA29 JA38 JA42 JA44 JB13 JB23 JB32 JB33 JBJ J38 KA05 KA07 KA16 KA18 KB14 MA05 MA08 MA13 MA17 MA27 MA35 MA37 MA41 NA04 NA25 NA27 PA03 QA06 QA18 5C094 AA03 AA06 AA10 AA12 AA13 AA43 AA48 BA03 BA43 CA19 CA24 DA13 DB01 DB04 EA04 EA05 EB07 EB01 EB07 EB07 EB02

Claims (15)

[Claims] 1. A substrate having a pair of opposed substrates and a liquid crystal sandwiched between the pair of substrates, wherein one substrate has a plurality of gate lines and a plurality of data lines substantially orthogonal to each other, A thin film transistor disposed near an intersection of a gate line and the data line; a pixel electrode and a common electrode which are disposed in parallel and alternately with each other in a region surrounded by the gate line and the data line to form a pixel region A liquid crystal display device of an IPS system, wherein the liquid crystal is rotated in a plane substantially parallel to the substrate by a voltage applied between the pixel electrode and the common electrode, at least one of the pair of substrates. A partition for dividing at least a part of the liquid crystal inside and outside the pixel region. 2. The liquid crystal display device according to claim 1, wherein the partition is formed so as to overlap with the common electrode when viewed from a normal direction of the substrate. 3. The device according to claim 1, wherein the partition is formed continuously so as to surround the pixel region.
Or the liquid crystal display device according to 2. 4. The apparatus according to claim 1, wherein the partition is formed so as to contact both of the pair of substrates.
4. The liquid crystal display device according to any one of items 3 to 3. 5. The liquid crystal display device according to claim 1, wherein the partition is made of an insulator. 6. A liquid crystal display device according to claim 5, wherein said insulator contains a resist or a photosensitive polyimide. 7. The method according to claim 1, wherein a color layer of a plurality of colors is provided on the substrate on the one side where the thin film transistor is formed, and the partition is formed of a color layer material deposited on the color layer. The liquid crystal display device according to claim 1. 8. The liquid crystal display device according to claim 7, wherein the color layer material forming the partition includes the color layer materials of a plurality of colors. 9. The liquid crystal display device according to claim 1, wherein the partition includes a conductor. 10. The liquid crystal display device according to claim 9, wherein said partition is disposed on said one side substrate and connected to said common electrode. 11. A step of forming a gate electrode and a common electrode on one substrate, a step of depositing a first insulating film on the gate electrode and the common electrode, and a step of forming a first insulating film on the first insulating film. Forming at least a step of forming a thin film transistor, a data line, and a pixel electrode; and a step of depositing a second insulating film on the data line and the pixel electrode, wherein a voltage is applied between the pixel electrode and the common electrode. A method of manufacturing a liquid crystal display device of an IPS system in which a liquid crystal sandwiched between the one substrate and an opposing substrate is rotated in a plane substantially parallel to the substrate by a voltage applied to the second insulating film. Forming a partition made of an insulator so as to overlap with the common electrode when viewed from the normal direction of the substrate. 12. A step of forming a gate electrode and a common electrode on one substrate, a step of depositing a first insulating film on the gate electrode and the common electrode, and a step of forming a first insulating film on the first insulating film. At least a step of forming a thin film transistor, a data line, and a pixel electrode; a step of forming an RGB color layer on the data line and the pixel electrode; and a step of depositing a planarization film on the color layer. An IPS system in which a liquid crystal sandwiched between the one side substrate and the opposing substrate is rotated in a plane substantially parallel to the substrate by a voltage applied between the pixel electrode and the common electrode. In the method of manufacturing a liquid crystal display device, when forming the color layer, the color layer of any one of RGB is formed in a region surrounded by the gate electrode and the data line, and viewed from a normal direction of the substrate. And the common electrode A method of manufacturing a liquid crystal display device, comprising a step of forming a partition by disposing a color layer material different in color from the one color layer so as to overlap. 13. A step of forming a gate electrode and a common electrode on one substrate, a step of depositing a first insulating film on the gate electrode and the common electrode, and a step of forming a first insulating film on the first insulating film. Forming at least a step of forming a thin film transistor, a data line, and a pixel electrode; and a step of depositing a second insulating film on the data line and the pixel electrode, wherein a voltage is applied between the pixel electrode and the common electrode. A method of manufacturing a liquid crystal display device of an IPS system in which a liquid crystal sandwiched between the one side substrate and the opposing substrate is rotated in a plane substantially parallel to the substrate by a voltage applied to the second insulating film. After the formation, a step of forming a groove penetrating to the common electrode in a region overlapping with the common electrode as viewed from the normal direction of the substrate, and a step of forming a partition made of a conductor inside and above the groove. It is characterized by including Of manufacturing a liquid crystal display device. 14. The liquid crystal device according to claim 11, wherein said partition is formed intermittently at a predetermined interval to provide a gap, and said liquid crystal is injected into a pixel region through said gap.
The method for manufacturing a liquid crystal display device according to any one of the above. 15. The liquid crystal display device according to claim 11, wherein the partition is formed at a height substantially equal to a gap between the one substrate and the opposing substrate. Manufacturing method.